Most communications systems use a transmitter and a receiver to transfer information across a transmission medium. The transmitter may interface with devices that send information over the transmission medium and may include a modulator to convert information from the devices into a format compatible with the transmission medium. Conversely, the receiver of a communication system may interface with devices that receive information, and may include a demodulator to convert information from the transmission medium into a format that the devices can use. Many modern communications systems consolidate the functionalities of a transmitter and a receiver into a transceiver that sends and receives information. In many communications systems, the transceiver may be capable of modulating and demodulating information between devices and the transmission medium.
In an ideal communications system, all of the modulated information placed in a transmission medium by a transmitter could be demodulated by a corresponding receiver without errors. That is, in an ideal world, a receiver could extract all the information placed on the transmission medium without any loss of information. In the real world, however, factors such as the components incorporated into the receiver, the environmental conditions surrounding the receiver, and the characteristics of the transmission medium may cause the receiver to lose some of the information placed on the transmission medium. It would be desirable to prevent loss of the information modulated into the transmission medium.